1. Field of the Invention
The present invention relates to an image recording apparatus having first and second bodies that are removably connected to each other such that the second body is disposed on an upper side of the first body wherein the second body is provided with components configured to perform at least one common function that is common to a plurality of types of image recording apparatuses while the first body is provided with components configured to perform at least one additional function that is other than the above-described at least one common function.
2. Discussion of Related Art
In an image recording apparatus such as an inkjet printer, ink droplets are ejected from a recording head toward each recording sheet that is conveyed along a conveying path whereby an image is recorded on each recording sheet.
JP-2007-90761A discloses an image recording apparatus including a lower unit and an upper unit which is disposed on an upper side of the lower unit. The upper unit has an inner space for accommodating therein a first sheet supplying cassette that is configured to hold recording sheets. With the first sheet supplying cassette being accommodated in the inner space of the upper unit, the recording sheets held by the first sheet supplying cassette are supplied to a conveying path that is defined in the upper unit. A recording head is provided to face the conveying path, and is reciprocably movable in a direction perpendicular to a conveying direction in which the recording sheets are to be conveyed. The recording head is operated to eject ink droplets toward each recording sheet while the recording sheet is being conveyed along the conveying path whereby an image is recorded on the recording sheet. After the image has been recorded on the recording sheet, the recording sheet is discharged onto the first sheet supplying cassette. The lower unit has an inner space for accommodating therein a second sheet supplying cassette that is also configured to hold recording sheets. With the second sheet supplying cassette being accommodated on the inner space of the lower unit, the recording sheets held by the second sheet supplying cassette are supplied to the conveying path that is defined in the upper unit. Each recording sheet supplied from the second sheet supplying cassette is subjected to an image recording operation performed by the recording head, in the same manner as each recording sheet supplied from the first sheet supplying cassette.
JP-2002-23440A discloses an image forming apparatus of electrophotographic type. Right and left foot portions are provided on a bottom plate of a main body of the apparatus in which a plurality of photosensitive drums are disposed. The right and left foot portions are in contact with an installed surface on which the apparatus is installed, so as to support the main body of the apparatus. A pair of rockable blocks are provided in the right and left foot portions, respectively, so as to be rockably supported by the respective foot portions. The pair of rockable blocks are connected to each other through an linkage plate so as to be movable together with each other. Each of the rockable blocks includes a downwardly projecting portion projecting downwardly through an opening that is formed through a bottom surface of a corresponding one of the right and left foot portions. Each of the rockable blocks has a contact surface which is located on a lower side of the corresponding foot portion and which is to be in contact with the installed surface. Where the installed surface (on which the apparatus is installed) has protrusions and recesses, the rockable blocks are rocked depending on such an irregularity of the surface, so that the main body of the apparatus is supported by the rockable blocks even if being somewhat tilted. That is, the protrusions and recesses of the installed surface are absorbed by the rockable blocks, whereby the main body of the apparatus can be prevented from being twisted. It is therefore possible to prevent disalignment between components of the apparatus such as the photosensitive drums and a scanner.
JP-2001-341377A discloses an image forming apparatus in which first and second foot portions are provided on a bottom surface of a main body of the apparatus. Each of the first and second foot portions has an inverted truncated cone shape. The first foot portion is made of rubber while the second foot portion is made of metal. The first foot portion protrudes downwardly from the bottom surface of the main body by a distance larger than a distance by which the second foot portion protrudes downwardly from the bottom surface of the main body. Therefore, the second foot portion can be prevented from being deformed by shock applied thereto upon installation of the apparatus. Further, since the second foot portion is made of metal while the first foot portion is made of rubber, it is possible to prevent the main body of the apparatus from being tilted by deformation of the first foot portion. This feature is effective to prevent problems such as jamming or inclined conveying of recording sheet which could be caused by tilting of the main body of the apparatus.
The image recording apparatus disclosed in JP-2007-90761A has small height and light weight, and is integrally formed of resin so as to be manufacturable at low cost. Further, since the inner spaces are defined in the respective upper and lower units, a body of each of the upper and lower units has a low rigidity and can be easily distorted thereby causing various problems. For example, the distortion of the body of the upper unit could reduce positional accuracy of a roller for conveying the recording sheets along the conveying path and positional accuracy of guide rails (guide rods) for slidably supporting a carriage carrying the recording head. The reduction of the positional accuracy of the roller could cause inclined conveying of the recording sheet. The reduction of the positional accuracy of the guide rails could affect quality of image recorded on each of the recording sheets. Further, the distortion of the body of the lower unit could make it impossible to reliably supply the recording sheets held by the second sheet supplying cassette, toward the conveying path. For solving such problems, it might be possible that the body of each of the upper and lower units is constituted by a frame made of steel or other metallic material. Where the body of each of the upper and lower units is constituted by the frame, the distortion of the body might be prevented by a certain degree. However, such a modification could cause other problems such as increase of weight of the apparatus and increase of manufacturing cost of the apparatus.
In these days, various types of image recording apparatuses are manufactured by manufacturers, for satisfying various needs of users. To this end, in the image recording apparatus disclosed in JP-2007-90761A, the upper unit constructed to perform common functions common to a plurality of types of image recording apparatuses and the lower unit constructed to supply the recording sheets from the second sheet supplying cassette toward the recording head are removably connected to each other, so that an image recording apparatus provided by only the upper unit as well as the image recording apparatus provided by the upper and lower units is manufactured as a product. That is, there is a case where the upper unit is used in the apparatus provided by only the upper unit and also a case where the upper unit is used in the apparatus provided by the upper and lower units. Therefore, each component of the upper unit has to be provided with a certain degree of positional accuracy where the apparatus is provided by only the upper unit, and each component of the upper and lower units has to be provided with a certain degree of positional accuracy where the apparatus is provided by the upper and lower units that are connected to each other.